Charged particle accelerators (including but not limited to linear particle accelerators) make wide use of RF resonant cavity structures. In these structures, RF power is directed to one or more resonant cavities, which are connected by a beam tube that allows charged particles to pass through each cavity. As a beam of particles traverses the acceleration gap in each cavity, it is accelerated by the voltage across the acceleration gap.
A linear particle accelerator (commonly referred to as a linac) is a type of particle accelerator that greatly increases the velocity of charged particles by subjecting them to oscillating electric fields along a beamline. Linacs have many applications, including but not limited to the generation of X-rays for medicinal purposes, the injection of particles for higher-energy accelerators, and the investigation of the properties of subatomic particles.
The design of a linac generally depends on the type of particle that is being accelerated, e.g. electrons, protons, or ions. Currently, common choices for industrial and medical electron linacs include the biperiodic design and the SCL (side-coupled linac) design. The final beam energy in these machines is typically in the 10-30 MeV range.
A linac design for these applications which results in better functionalities, including but not limited to RF efficiency, higher rates of acceleration, smaller weight or volume, easier manufacturability, and enhanced reliability, is desirable for many applications.